It happened now several times recently that on my K51 the right front brake drum was jamming hard (kind of blockade) when I just tipped on the brake pedal. Mostly when the car stood for a couple of weeks. I cannot unlock it again, except I drive backward. The brake adjustment is proper, had always a nicely balanced braking rate. Master and wheelcylinder are obviously dry, no liquid leakage visible. brakehosing is intact too. brakeshoes and lining looks thick enough when I check through the inspection gap. Does anyone know if this is a known phenomenon with Kaiser 51? Thanks and regards, Adrian, Bülach - Switzerland